Impaired lung epithelial permeability in diabetics detected by technetium-99m-DTPA aerosol scintigraphy.

Abstract

The clearance of inhaled 99mTc-diethyl triaminepentaacetic acid (DTPA) aerosol from the lungs is used as an index of lung epithelial permeability. We investigated the involvement of the lung in diabetic patients using 99mTc-DTPA aerosol scintigraphy. A total of 33 diabetic patients were studied. Thirteen had complications such as retinopathy and/or nephropathy (Group A) and 20 were without complications (Group B). As a control group, 20 healthy nonsmokers were studied. Dynamic scintigrams (2 min/frame, up to 30 min) were obtained following inhalation of 99mTc-DTPA through a radioaerosol delivery system. Time-activity curves were obtained and half-time (T1/2) of DTPA was measured from the curves. The mean T1/2 values (min +/- s.d.) were calculated to be 133.05 +/- 46.97, 93.67 +/- 21.23, 91.97 +/- 18.21 (Group A, Group B and controls, respectively). The mean T1/2 of Group A was significantly longer than controls (p < 0.005) and than that of Group B (p < 0.005) indicating decreased epithelial permeability. No such statistical difference was detected between Group B and controls (p > 0.05). The lung is a target organ in diabetes and lung involvement is closely related to other vascular complications. The presence of lung involvement can be readily detected by 99mTc-DTPA aerosol scintigraphy.